"In the age of Facebook, many Americans seem to opt for a broad, shallow networking strategy," Shigehiro Oishi of the University of Virginia and Selin Kesebir of the London Business School and colleagues wrote in the study.

"Yet, cross-cultural research has shown that having many friends is not always viewed positively outside the United States," researchers wrote, adding that people who claimed to have more than 50 friends on Facebook were perceived as "naïve" and "foolish" in Ghana.

Researchers said that the recent study found that the number of friends a person has might depend on their social and financial conditions.

Oishi speculates that the reason why American social networking users prefer having more Facebook friends may be due to the simple fact that people living in the U.S. move around a lot, citing a 2001 study that found that around half of Americans move to a new place to live in any five-year period.

Additionally, the study revealed that a person's economic conditions at a given time might be another important factor in determining the number of friends they have.

"When times are prosperous, your friends are less likely to need much help, whether it's covering a hospital bill or providing babysitting, and so a broad network of friends is easy to maintain," Oishi and co-researcher and Selin Kesebir of the London Business School wrote. "But when times aren't as flush, having more friends might incur huge costs in terms of both time and resources."

Researchers hypothesized that a broad, shallow networking strategy frequently employed by American social networking users would be optimal for people living in residentially mobile and economically favorable conditions.

On the other hand, having a small but deep networking strategy would benefit those who rarely move and live in places with less favorable economic conditions.

After simulating a variety of people who have different number of friends at different levels of friendship, and measuring the investment required by each type of friendship, researcher confirmed what they predicted: that having small social network with deep ties to friends is more beneficial to people living in unstable economic conditions and who have friends who are less likely to move away.

The simulation also revealed that, regardless of a person's financial situation, having a large social network with shallower ties to friends is more beneficial for those who have friends who are more likely to move away.

To see whether the finding reflects what actually happens in the real world, researchers surveyed 247 Americans with an average age of 31 in a second study.

Participants were asked to list one very close friend, one close friend and one distant friend. Researcher then asked participants to imagine that their time, energy and money were limited to 60 points, and to distribute the points among these three friends. Participants' subjective well-being was also measured, using a combination of three measures: life satisfaction, experiences of positive emotions and lack of experiences of negative emotions.

Researchers also examined census data to assess how often people moved around and for family income in each of the ZIP code studied.

The results of the second study were similar to those in the first study, after the researchers found that people living in areas with less mobility and lower incomes, were happier when they had fewer, but close friends compared to those with more, but more distant friends.

However, researchers noted that a broad, shallow friendship strategy was associated with subjective well-being in all of the three other conditions, such as low income-unstable, high income-stable, high income-unstable.

Researchers say that the two studies reveal that the role socioeconomic factors like residential mobility and economic security can accurately determine the most adaptive networking strategy.

"As residential mobility decreases and economic recession deepens in the United States, the optimal social-networking strategy might shift from the broad-but-shallow to the narrow-but-deep, even in a nation known best for the strength of weak ties," researchers conclude.